[PyMOL] Finding distances along molecular tunnels

[Sajeewa P. <saj...@gm...>]

Hello everyone,

I have 2 molecular tunnels inside one protein corresponding to two starting
points, created by the CAVER plugin. The two tunnels join to form one
common tunnel.

I want to measure

1) The distance between the two starting points of the tunnels

2) The distance from each starting point to the junction

If I follow wizard --> measurements --> distance it asks for atoms to click
on, but as the tunnels are empty space when I click on the starting points
of the tunnels nothing is recognized.
What would be the most accurate way of measuring the above two distances?

Thank you

Sajeewa Dewage